ST. LOUIS — After walking Pedro Alvarez four straight times, the St. Louis Cardinals pitched to the Pittsburgh Pirates slugger. Lesson learned.

Besides setting a career high in walks, Alvarez also homered in the 12th inning, doing his part in another elongated losing cause.

“You don’t just put a guy on every time,” manager Clint Hurdle said after losing in extra innings for the third straight time, 3-2 in the 14th on Sunday.

“I mean, we’re not just talking about (Barry) Bonds back in the day, we’re talking about a young player that’s had some success against the team.”

Alvarez has 16 career homers against the Cardinals, topped only 17 against Milwaukee among opponents. He leads National League players with 38 homers in day games the last four seasons after hitting his fifth of the season off rookie Sam Tuivailala.

“There’s a lot of things they pay attention to,” Hurdle said. “You figure there’s a certain guy in certain situations that you don’t want let beat you, and he’s obviously has been that guy.”

The Pirates had plenty of baserunners, totaling 11 hits with four walks, but left 13 on base.

“We just need to keep working at it because obviously we’re getting them out there,” Hurdle said. “We’ve got to find a way to plate them.”

Kolten Wong homered off Radhames Liz (1-2) in the 14th inning for his second career game-winning homer.

The Cardinals swept a three-game series all in extra innings for the first time in franchise history. They’re the first team to do it since June 4-7, 1925, when the Cincinnati Reds beat the Boston Braves, according to STATS.

The Cardinals posted three extra-inning wins in a row for the first time since July 2006, when they twice beat Houston before the All-Star break and then won at Dodger Stadium when play resumed.

The NL Central leaders are a major league-best 18-6, matching the franchise’s best 24-game start since 1900. They had the same record in 1941 and 1944.

The Cardinals tied it on a bases-loaded single by Peter Bourjos in the bottom half. St. Louis left the bases loaded in the 11th and again in the 12th.

The finale of a three-game series that totaled 35 innings lasted 4 hours and 28 minutes.

Wong hit his second homer with one out, sending a pitch from Liz into the home bullpen in right.

Rookie Miguel Socolovich (1-0) worked a perfect 14th to earn his first career victory.

Bourjos’ tying infield hit against Liz ticked off the glove of diving third baseman Josh Harrison.

Jung Ho Kang’s first homer came on the first pitch of the ninth from Cardinals closer Trevor Rosenthal. It’s the first blown save in nine chances for Rosenthal and first homer allowed.

“The timing was perfect and I got a good swing on it,” Kang said through a translator. “It felt good to go around the bases for a home run, but we lost.”

Pirates starter Vance Worley gave up a run on four hits in six innings. St. Louis starter Michael Wacha allowed five hits in 6 2-3 scoreless innings.

Matt Carpenter hit his fourth homer leading off the fourth. He was removed in a double switch after seven innings after experiencing light-headedness.

Center fielder Andrew McCutchen’s glove popped off as he attempted to reach over the wall for Carpenter’s fourth homer. The shot ended a run of 95 consecutive innings in 11 games by Pirates pitchers without allowing a longball.

McCutchen lost his mitt again just missing a diving catch on Jhonny Peralta’s bloop single in the seventh.

Harrison was 0 for 7 with two strikeouts and only two balls hit to the outfield. Shortstop Jordy Mercer flubbed two popups that dropped in for gift singles, the first perhaps lost in the sun but the second after shadows had descended on Busch Stadium.